1. Field of the Invention
The invention lies in the field of electron beam resist compositions and the production of patterned thin film layers thereof.
2. Prior Art
The prior art is replete with radiation sensitive materials as resists and with their use in pattern formation in the fabrication of microelectronic devices. In the prior art, pattern formation in these materials is dependent upon differential solubility between irradiated and unirradiated regions. These solubility changes are produced by either bondbreaking, (chain scission) or bond formation (chain crosslinking) in polymeric systems. This occurs in the presence of actinic radiation, E-beam radiation or X-ray radiation.
The prior art materials have several drawbacks among which is the difficulty of obtaining sharp images of high resolution, particularly in negative resists. This is due to the swelling of the polymeric material during solvent development. Films of prior art materials are generally insulative in nature and as such tend to buildup static charges on their surfaces during irradiation. In the prior art this problem is overcome by the deposition of a thin metal film on top of the polymeric resist material. In addition it is difficult to produce films of uniform thickness by solvent coating techniques on surfaces with topography.
The state of the art in electron-beam lithography can be readily reviewed in a review entitled "CRC Critical Reviews" M. J. Bowden, Solid State and Material Sciences, 8, 223 (1979).